All too often, I see investors heading in the wrong direction en masse. They buy stocks at the top of the market or bonds when interest rates are heading up.

Occasionally, though, active investors may be heading in the right direction. A case in point has been the flow of money into certain exchange-traded funds in the first half of this year.

Reflecting most hot money trends, billions of dollars moved because of headlines. The Energy Select SPDR exchange-traded fund, which I discussed three weeks ago, gathered more than $3 billion in assets in the first half, when crude oil prices climbed and demand for hydrocarbons remained high.

The Energy SPDR, which charges 0.16 percent for annual management expenses and holds Exxon Mobil Corp, Chevron Corp and Schlumberger NV, has climbed 22 percent in the past 12 months, with nearly one-third of that gain coming in the three months through July 18. Long-term, this may be a solid holding as developing countries such as China and India demand more oil.

"We think the Energy Select SPDR is a play of oil prices remaining high and supporting growth for integrated oil & gas and exploration and production companies," analysts from S&P Capital IQ said in a recent "MarketScope Advisor" newsletter.

Headlines also favored European stocks as represented by the Vanguard FTSE Developed Markets ETF, which holds leading eurozone stocks such as Nestle SA, Novartis AG and Roche Holding AG. The fund has been the top asset gatherer thus far this year, with $4 billion in new money, according to S&P Capital IQ.

As Europe continues to recover over the next few years and the European Central Bank keeps rates low, global investors will continue to benefit from this growing optimism.

The Vanguard fund has gained nearly 16 percent for the 12 months through July 18. It charges 0.09 percent in annual expenses and is a solid holding if you have little or no European exposure in your stock portfolio.

Rate Hikes

Not all hot money trends make sense, however. As the economy accelerates and interest-rate hikes look increasingly likely, investors are still piling money into bond funds, which lose money under those circumstances.